Speed Density - Blowthrough MAF
By: Mark Gibson, Gibspeed Automotive Solutions
After making an intake and dp for my car, I decided to turn the MAF off and go full Speed Density. This was mostly because I'm using a larger-than-stock dia MAF housing and wanted to do some testing for larger setups. Not sure how many are doing this, but driveability is phenomenal, even better than bone stock with the MAF. This will also make it incredibly easy to modify the tune for bigger intercooler, turbo, TB, IM, etc etc.
The only downside was cruise control will not engage. I opened a ticket with HPT on this and they came back to me with 2 cruise control patches today (which made me think to post here). UPDATE: These both work and just just need a "write entire" to apply them.
I know a lot of people just concede to using the intakes with just the elbow being upgraded but keeping the stock MAF/box (though there are a few stock dia full intakes that work fine too), but this was my way around all that while also increasing flexibility for future hardware changes.
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Info on how to switch to SD below:
1. Eng Diag>Airflow>Set MAF Fail High to 1hz
2. Eng Diag>DTC's>P0101,P0102,P0103 = MIL on First Error, Uncheck SES
3. Eng>Airflow>Gen>Zero out MAF Freq. Table
4. Eng>Airflow>Dynamic>Set High RPM Enable/Disable to near redline.
5. Eng>Airflow>Electronic Throttle>PR Limts>Set both to 1 to avoid throttle closing from MAF faults.
6. OS>TCS and Cruise Ctrl Patches = Applied, Patched,Patched (Just need to download the latest HPT beta for these patches)
7. Write Entire
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Note, You'll want to set up a histogram to log fuel trims vs PR/RPM to work on your VVE tables and dial in your SD tune. There are also very likely some other small changes that will need to be made for an Automatic trans. I have not played with one yet, but I'd be willing to bet some trans-related parameters need to be adjusted.
